1. Field of the Invention
The present invention relates to an acoustic data processor and an acoustic data processing method for processing acoustic data containing signal sounds to reduce noises generated by a mechanical apparatus such as a robot.
2. Background Art
For example, a robot which performs automatic speech recognition while moving has to be provided with ability to suppress noises caused by its own motion, that is, ego-noises (for example, Japanese patent application laid open 2008-122927).
In general, sound source localization and sound source separation have been studied to reduce noises. However, automatic speech recognition under ego-noise is not mainly addressed (for example, I. Hara, F. Asano, H. Asoh, J. Ogata, N. Ichimura, Y. Kawai, F. Kanehiro, H. Hirukawa, and K. Yamamoto, “Robust speech interface based on audio and video information fusion for humanoid HRP-2” in Proc. IEEE/RSJ International Joint Conference on Robots and Intelligent Systems (IROS), pp. 2404-2410, (2004)). Conventional noise reduction methods such as spectral subtraction do not function successfully in many actual cases (for example, S. Boll, “Suppression of Acoustic Noise in Speech Using Spectral Subtraction”, in IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. ASSP-27, No. 2, (1979)). Further, there is a method in which spectral subtraction is performed for each behavior. However, it is practically unfeasible to handle various kinds of behaviors. Besides, ego-noise sources exist in the near-field of the robot and thus the performance of the conventional far-field noise reduction solutions drops considerably.
Thus, an acoustic data processor and an acoustic data processing method for processing acoustic data containing signal sounds to reduce noises generated by a mechanical apparatus, such as ego-noises of a robot, have not been developed.
Accordingly, there is a need for an acoustic data processor and an acoustic data processing method for processing acoustic data containing signal sounds to reduce noises generated by a mechanical apparatus, ego-noises of a robot, for example.